then by your logic, there's no point in investing in magic units, except for Micaiah because she's forced.
I'm pretty sure that the only mages in the game that are considered average-above average overall are Soren [it seems all the combat oriented GMs are decent-ish], maybe Micaiah, and maybe a bexp dumped Illyana [but those growths are shit. And the main selling point is availibility+Rexthunder iirc.] and Calil [iirc, fire magic specilist mages are the only ones with a 34 spd cap. Snaki not counting. She's also got a fair amount of usefulness with Meteor.] Laura/Rhys are mediocre at best [Rhys has growths close to Miccy, and Laura isn't exactly the best choice to pump bexp into for the DB in HM. Saints also have crap caps.], Oliver/Bastion/Pelleas suck, and Tormod is NEVER around. What'shisface is around for a bit of 4-E, but it's so late in the game and who fucking cares by that point. Nasir's a magic powered unit, but he's valued for white tide.